The proposal on the table is not to have only one pilot on the flight. It's to have only one on duty during cruise phase only while the other one rests. This way they can skip the full double crew requirement during long haul.
So during takeoff and landing the cockpit will still be fully staffed. And in an emergency the resting pilot can be called. Toilet breaks would be covered by the other pilot too. So the cockpit is never empty. Doesn't sound like such a bad idea imo. During cruise the plane is normally flying itself from waypoint to waypoint anyway. Though I wonder how much quality of rest you can get in such a scenario (having to be woken up for every toilet break etc)
There will also be a remote hands support center, I'm less confident about that idea but as long as it's extra and not counted on it might be a good option.